Cobb County, GA Zoning Overlays & Bonuses: Density Bonus Law (2026)

Cobb County Code of Ordinances § 134-204(10) governs the RM-8 residential multifamily district and grants a density bonus for redevelopment: condominiums and townhomes constructed to replace existing or demolished multifamily dwelling units are eligible for up to 15 percent more units than the number demolished, subject to site plan approval by the Board of Commissioners. The identical clause appears at § 134-206(10) for the RM-12 district. The bonus rides on top of each district's base cap, not instead of it: RM-8 permits a maximum of eight dwelling units per acre and RM-12 permits 12 units per acre under § 134-204(12)a. and § 134-206(12)a., respectively, so a 100-unit RM-8 complex demolished and rebuilt as condos could add up to 15 replacement units above the torn-down count, still measured against the acreage-based cap.

The bonus is not automatic. It flows from a site plan the applicant submits and the Board of Commissioners approves at a regularly scheduled meeting, per § 134-126, and any later change to that site plan beyond a minor modification must go back through the full rezoning/site plan process. Because approval is a board decision tied to the underlying zoning case, a denial or a condition attached to the approval can be appealed to Cobb County Superior Court under § 134-127, but the appeal must be filed within 30 days of the Board's vote or the decision becomes final.

The rule applies only to condominiums and townhomes built to replace multifamily units that already existed or were torn down; it does not create extra density for ground-up multifamily projects on vacant or non-multifamily land, and it reaches only the RM-8 and RM-12 districts. It also applies only in unincorporated Cobb County. Marietta, Smyrna, Kennesaw, Acworth, Powder Springs and Austell each administer their own zoning code and none carries this specific bonus language.